Teleconvertors

I have heard conflicting comments about using TCs and Lenses from matching manufacturers and the impact mixing and matching might have upon IQ.

I am looking to add a 1.4tc to my armoury and given I have Canon and Sigma lenses am not too sure in which direction to go!!

Will there be any difference in IQ if I buy the Canon teleconvertor and use it with the Sigma 120-300 as opposed to using the Sigma teleconvertor with the Sigma lens?

And vice versa with my 70-200L.....will that be happier nuzzling away against a
Canon telecon than I Sigma one?!?

Any thoughts and advice would be greatfully received!!

Perhaps you've already read it, but I found this quite useful and informative. https://photography-on-the.net/forum/showthre​ad.php?t=41922

Don´t worry, your lenses takes the x1,4 TC pretty well, even you are going not to be able to see any IQ degradation. I think for the comments of all over here that Canon, Sigma & Kenko works very well. I have the Kenko 1,4 TC DG 300 Pro and over my EF 70-200 f/4 L and EF 300 f/4 L IS works very well (and I have f/4 lenses, not like you).

For almost $100 I did pay, I can not say anymore: very good price/IQ

One example over the 70-200 f/4

One reason I have 5 TC's is that I have found different TC's work best on different lenses - there is no single best TC. I had the Sigma 120-300 and my (sometimes poor) memory says the Canon and Tamron SP 1.4x were best on that lens. But, it might depend on your lens, camera, etc.

Thanks for the feedback and help everyone - will have a look at the Tamron and the Kenko ones too.